Prior art patent document published WO 2015/132092 A2 discloses a cover for a gas cylinder tap. The cover comprises a shell for housing the tap and a hook pivotally mounted on the shell, the hook being configured for securing the gas cylinder to a horizontal bar, like a bar of a hospital bed. The shell comprises reservations on its external surface configured for receiving the hook in a folded position so as to generally conform to said external surface. The invention is also directed to a gas storage assembly comprising a gas cylinder, a tap and a cover. The shell comprises an upper half-shell and a lower half-shell joined together. The tap comprises a pressure reducer and a rotatable hand-wheel for actuating a flow-selector, said hand-wheel being on the upper half-shell. The tap comprises also an outlet connector of the hose barb type extending through an opening of the upper half-shell.
Prior art patent document published WO 2015/132285 A1 discloses a device for regulating the pressure and/or flow of pressurized gas, comprising a body with a gas inlet, a gas outlet and a gas passage the outlet with the inlet, a pressure reducer and a flow-selector arranged downstream of the pressure reducer, a hand-wheel rotatably mounted on the body and cooperating with the flow-selector for adjusting said flow, and a pressure indicator located at the centre of the hand-wheel. The device comprises also a shaft rigidly fixed to the body and rotatably bearing the hand-wheel, said shaft supporting the flow-selector and comprising a gas channel fluidly connected to the gas passage in the body.
None of the above mentioned teachings discloses details about the hand-wheel, in particular about possible indicia providing reference marks for its angular position. For most applications, in particular for medical applications, the outlet pressure and/or flow-rate is a critical information for a proper use.
Indicia are often printed on the outer surface of the hand-wheel. That surface is often of a dark colour and the indicia are often printed in white for providing contrast. Further to a repetitive use of the tap, the indicia can wear out and almost disappear, potentially leading to the delivery of a not adapted flow-rate and/or pressure.